DEAR DR. THOMPSON: My dog was just diagnosed with mange. My veterinarian says it is not contagious to my other dog, but I am still worried. How did he get mange if it is not contagious?
ANSWER: What you are describing is demodectic mange. It is a common skin problem in young dogs. There are two forms of the disease: focal and generalized. The disease begins when a mite overgrows in the hair follicle, leading to hair loss or bald patches. Itching usually accompanies the hair loss. In young dogs, the focal form rarely requires treatment. As the puppies' immune systems develop, the overgrowth of the mange mite will resolve naturally. Generalized mange covers large parts of the body. Treatment may involve medicated dips for weeks. An oral medication is very effective but is considered an off-label treatment by the FDA. (Off-label treatment is the use of a medication for a purpose other than what is approved.) As the mites are controlled, normal hair will return over a period of weeks to months.
An adult form occurs in older dogs and can be difficult to manage. These mites do not normally overgrow in an adult dog with a normal immune system. Medications that suppress the immune system or diseases that interfere with normal defenses will allow the mites to proliferate. Unless the underlying cause is found, the mange will continue to be a problem.
Your veterinarian will do skin scrapings and evaluate the mite numbers under the microscope to assess how well treatment is progressing. Some contagious diseases like ringworm or sarcoptic mange can look very similar. Some further testing may be needed if your pet is not responding as expected. In young dogs, once the hair loss and infection have been resolved, recurrence is unusual. Some scarring may be a long-term consequence. For older pets, the long-term outlook depends on the underlying disease. Diseases of the immune system can be serious problems. What may appear to be a skin infection may involve more testing to evaluate your pet's immune system.
DEAR DR. THOMPSON: We have three cats and one has started having accidents outside the litter box. Is she getting even with us or could there be something wrong?
ANSWER: This question is one veterinarians dread. Inappropriate litter-box habits are the No. 1 reason cats are surrendered or euthanized. The first step is to determine if a physical problem has developed that is causing your cat to urinate excessively or have painful urinations. A number of diseases can lead to trouble including; kidney problems, diabetes, smoldering bladder infections, bladder stones, or idiopathic cystitis. Idiopathic cystitis is an inflammatory condition of the bladder that occurs in the absence of infection. I compare the problem to an irritable bladder syndrome, which is very common in many middle-aged cats.
Once you have eliminated a physical problem, the next step is to address your location, number, and type of boxes. You should have one more box than you have cats. There should be one on each floor. Most of the litters and boxes we choose are perfumed, allowing us to change litter less frequently, which leads to problems. We place boxes next to noisy washing machines or furnaces which can frighten cats. We stick them in basements or laundry rooms far away from where cats spend much of their time. Cats can be very territorial and litter box guarding can occur forcing the less dominant cat to find a new place to go or risk retribution from the alpha cat.
Unfortunately, many litter box problems boil down to human error. Scooping often and respecting cat behavior in multiple-cat homes will eliminate many problems. If these do not help there are some medications which can help your cat overcome anxiety with your litter or cat social structure which your veterinarian can help you find.
Questions for Dr. Thompson can be e-mailed to firstname.lastname@example.org or mailed to The Blade, Attn. Ask the Vet, 541 North Superior St., Toledo, OH 43660. Dr. Thompson regrets that he cannot answer individual letters.